<?php
/**
 * This is the PHP OpenID library by JanRain, Inc.
 *
 * This module contains core utility functionality used by the
 * library.  See Consumer.php and Server.php for the consumer and
 * server implementations.
 *
 * PHP versions 4 and 5
 *
 * LICENSE: See the COPYING file included in this distribution.
 *
 * @package OpenID
 * @author JanRain, Inc. <openid@janrain.com>
 * @copyright 2005-2008 Janrain, Inc.
 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
 */

/**
 * The library version string
 */
define('Auth_OpenID_VERSION', '2.1.2');

/**
 * Require the fetcher code.
 */
require_once "Auth/Yadis/PlainHTTPFetcher.php";
require_once "Auth/Yadis/ParanoidHTTPFetcher.php";
require_once "Auth/OpenID/BigMath.php";
require_once "Auth/OpenID/URINorm.php";

/**
 * Status code returned by the server when the only option is to show
 * an error page, since we do not have enough information to redirect
 * back to the consumer. The associated value is an error message that
 * should be displayed on an HTML error page.
 *
 * @see Auth_OpenID_Server
 */
define('Auth_OpenID_LOCAL_ERROR', 'local_error');

/**
 * Status code returned when there is an error to return in key-value
 * form to the consumer. The caller should return a 400 Bad Request
 * response with content-type text/plain and the value as the body.
 *
 * @see Auth_OpenID_Server
 */
define('Auth_OpenID_REMOTE_ERROR', 'remote_error');

/**
 * Status code returned when there is a key-value form OK response to
 * the consumer. The value associated with this code is the
 * response. The caller should return a 200 OK response with
 * content-type text/plain and the value as the body.
 *
 * @see Auth_OpenID_Server
 */
define('Auth_OpenID_REMOTE_OK', 'remote_ok');

/**
 * Status code returned when there is a redirect back to the
 * consumer. The value is the URL to redirect back to. The caller
 * should return a 302 Found redirect with a Location: header
 * containing the URL.
 *
 * @see Auth_OpenID_Server
 */
define('Auth_OpenID_REDIRECT', 'redirect');

/**
 * Status code returned when the caller needs to authenticate the
 * user. The associated value is a {@link Auth_OpenID_ServerRequest}
 * object that can be used to complete the authentication. If the user
 * has taken some authentication action, use the retry() method of the
 * {@link Auth_OpenID_ServerRequest} object to complete the request.
 *
 * @see Auth_OpenID_Server
 */
define('Auth_OpenID_DO_AUTH', 'do_auth');

/**
 * Status code returned when there were no OpenID arguments
 * passed. This code indicates that the caller should return a 200 OK
 * response and display an HTML page that says that this is an OpenID
 * server endpoint.
 *
 * @see Auth_OpenID_Server
 */
define('Auth_OpenID_DO_ABOUT', 'do_about');

/**
 * Defines for regexes and format checking.
 */
define('Auth_OpenID_letters', "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");

define('Auth_OpenID_digits', "0123456789");

define('Auth_OpenID_punct', "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~");

if (Auth_OpenID_getMathLib() === null) {
  Auth_OpenID_setNoMathSupport();
}

/**
 * The OpenID utility function class.
 *
 * @package OpenID
 * @access private
 */
class Auth_OpenID {

  /**
   * Return true if $thing is an Auth_OpenID_FailureResponse object;
   * false if not.
   *
   * @access private
   */
  function isFailure($thing) {
    return is_a($thing, 'Auth_OpenID_FailureResponse');
  }

  /**
   * Gets the query data from the server environment based on the
   * request method used.  If GET was used, this looks at
   * $_SERVER['QUERY_STRING'] directly.  If POST was used, this
   * fetches data from the special php://input file stream.
   *
   * Returns an associative array of the query arguments.
   *
   * Skips invalid key/value pairs (i.e. keys with no '=value'
   * portion).
   *
   * Returns an empty array if neither GET nor POST was used, or if
   * POST was used but php://input cannot be opened.
   *
   * @access private
   */
  function getQuery($query_str = null) {
    $data = array();
    
    if ($query_str !== null) {
      $data = Auth_OpenID::params_from_string($query_str);
    } else if (! array_key_exists('REQUEST_METHOD', $_SERVER)) {
      // Do nothing.
    } else {
      // XXX HACK FIXME HORRIBLE.
      //
      // POSTing to a URL with query parameters is acceptable, but
      // we don't have a clean way to distinguish those parameters
      // when we need to do things like return_to verification
      // which only want to look at one kind of parameter.  We're
      // going to emulate the behavior of some other environments
      // by defaulting to GET and overwriting with POST if POST
      // data is available.
      $data = Auth_OpenID::params_from_string($_SERVER['QUERY_STRING']);
      
      if ($_SERVER['REQUEST_METHOD'] == 'POST') {
        $str = file_get_contents('php://input');
        
        if ($str === false) {
          $post = array();
        } else {
          $post = Auth_OpenID::params_from_string($str);
        }
        
        $data = array_merge($data, $post);
      }
    }
    
    return $data;
  }

  function params_from_string($str) {
    $chunks = explode("&", $str);
    
    $data = array();
    foreach ($chunks as $chunk) {
      $parts = explode("=", $chunk, 2);
      
      if (count($parts) != 2) {
        continue;
      }
      
      list($k, $v) = $parts;
      $data[$k] = urldecode($v);
    }
    
    return $data;
  }

  /**
   * Create dir_name as a directory if it does not exist. If it
   * exists, make sure that it is, in fact, a directory.  Returns
   * true if the operation succeeded; false if not.
   *
   * @access private
   */
  function ensureDir($dir_name) {
    if (is_dir($dir_name) || @mkdir($dir_name)) {
      return true;
    } else {
      $parent_dir = dirname($dir_name);
      
      // Terminal case; there is no parent directory to create.
      if ($parent_dir == $dir_name) {
        return true;
      }
      
      return (Auth_OpenID::ensureDir($parent_dir) && @mkdir($dir_name));
    }
  }

  /**
   * Adds a string prefix to all values of an array.  Returns a new
   * array containing the prefixed values.
   *
   * @access private
   */
  function addPrefix($values, $prefix) {
    $new_values = array();
    foreach ($values as $s) {
      $new_values[] = $prefix . $s;
    }
    return $new_values;
  }

  /**
   * Convenience function for getting array values.  Given an array
   * $arr and a key $key, get the corresponding value from the array
   * or return $default if the key is absent.
   *
   * @access private
   */
  function arrayGet($arr, $key, $fallback = null) {
    if (is_array($arr)) {
      if (array_key_exists($key, $arr)) {
        return $arr[$key];
      } else {
        return $fallback;
      }
    } else {
      trigger_error("Auth_OpenID::arrayGet (key = " . $key . ") expected " . "array as first parameter, got " . gettype($arr), E_USER_WARNING);
      
      return false;
    }
  }

  /**
   * Replacement for PHP's broken parse_str.
   */
  function parse_str($query) {
    if ($query === null) {
      return null;
    }
    
    $parts = explode('&', $query);
    
    $new_parts = array();
    for ($i = 0; $i < count($parts); $i ++) {
      $pair = explode('=', $parts[$i]);
      
      if (count($pair) != 2) {
        continue;
      }
      
      list($key, $value) = $pair;
      $new_parts[$key] = urldecode($value);
    }
    
    return $new_parts;
  }

  /**
   * Implements the PHP 5 'http_build_query' functionality.
   *
   * @access private
   * @param array $data Either an array key/value pairs or an array
   * of arrays, each of which holding two values: a key and a value,
   * sequentially.
   * @return string $result The result of url-encoding the key/value
   * pairs from $data into a URL query string
   * (e.g. "username=bob&id=56").
   */
  function httpBuildQuery($data) {
    $pairs = array();
    foreach ($data as $key => $value) {
      if (is_array($value)) {
        $pairs[] = urlencode($value[0]) . "=" . urlencode($value[1]);
      } else {
        $pairs[] = urlencode($key) . "=" . urlencode($value);
      }
    }
    return implode("&", $pairs);
  }

  /**
   * "Appends" query arguments onto a URL.  The URL may or may not
   * already have arguments (following a question mark).
   *
   * @access private
   * @param string $url A URL, which may or may not already have
   * arguments.
   * @param array $args Either an array key/value pairs or an array of
   * arrays, each of which holding two values: a key and a value,
   * sequentially.  If $args is an ordinary key/value array, the
   * parameters will be added to the URL in sorted alphabetical order;
   * if $args is an array of arrays, their order will be preserved.
   * @return string $url The original URL with the new parameters added.
   *
   */
  function appendArgs($url, $args) {
    if (count($args) == 0) {
      return $url;
    }
    
    // Non-empty array; if it is an array of arrays, use
    // multisort; otherwise use sort.
    if (array_key_exists(0, $args) && is_array($args[0])) {
      // Do nothing here.
    } else {
      $keys = array_keys($args);
      sort($keys);
      $new_args = array();
      foreach ($keys as $key) {
        $new_args[] = array($key, $args[$key]);
      }
      $args = $new_args;
    }
    
    $sep = '?';
    if (strpos($url, '?') !== false) {
      $sep = '&';
    }
    
    return $url . $sep . Auth_OpenID::httpBuildQuery($args);
  }

  /**
   * Implements python's urlunparse, which is not available in PHP.
   * Given the specified components of a URL, this function rebuilds
   * and returns the URL.
   *
   * @access private
   * @param string $scheme The scheme (e.g. 'http').  Defaults to 'http'.
   * @param string $host The host.  Required.
   * @param string $port The port.
   * @param string $path The path.
   * @param string $query The query.
   * @param string $fragment The fragment.
   * @return string $url The URL resulting from assembling the
   * specified components.
   */
  function urlunparse($scheme, $host, $port = null, $path = '/', $query = '', $fragment = '') {
    
    if (! $scheme) {
      $scheme = 'http';
    }
    
    if (! $host) {
      return false;
    }
    
    if (! $path) {
      $path = '';
    }
    
    $result = $scheme . "://" . $host;
    
    if ($port) {
      $result .= ":" . $port;
    }
    
    $result .= $path;
    
    if ($query) {
      $result .= "?" . $query;
    }
    
    if ($fragment) {
      $result .= "#" . $fragment;
    }
    
    return $result;
  }

  /**
   * Given a URL, this "normalizes" it by adding a trailing slash
   * and / or a leading http:// scheme where necessary.  Returns
   * null if the original URL is malformed and cannot be normalized.
   *
   * @access private
   * @param string $url The URL to be normalized.
   * @return mixed $new_url The URL after normalization, or null if
   * $url was malformed.
   */
  function normalizeUrl($url) {
    @$parsed = parse_url($url);
    
    if (! $parsed) {
      return null;
    }
    
    if (isset($parsed['scheme']) && isset($parsed['host'])) {
      $scheme = strtolower($parsed['scheme']);
      if (! in_array($scheme, array('http', 'https'))) {
        return null;
      }
    } else {
      $url = 'http://' . $url;
    }
    
    $normalized = Auth_OpenID_urinorm($url);
    if ($normalized === null) {
      return null;
    }
    list($defragged, $frag) = Auth_OpenID::urldefrag($normalized);
    return $defragged;
  }

  /**
   * Replacement (wrapper) for PHP's intval() because it's broken.
   *
   * @access private
   */
  function intval($value) {
    $re = "/^\\d+$/";
    
    if (! preg_match($re, $value)) {
      return false;
    }
    
    return intval($value);
  }

  /**
   * Count the number of bytes in a string independently of
   * multibyte support conditions.
   *
   * @param string $str The string of bytes to count.
   * @return int The number of bytes in $str.
   */
  function bytes($str) {
    return strlen(bin2hex($str)) / 2;
  }

  /**
   * Get the bytes in a string independently of multibyte support
   * conditions.
   */
  function toBytes($str) {
    $hex = bin2hex($str);
    
    if (! $hex) {
      return array();
    }
    
    $b = array();
    for ($i = 0; $i < strlen($hex); $i += 2) {
      $b[] = chr(base_convert(substr($hex, $i, 2), 16, 10));
    }
    
    return $b;
  }

  function urldefrag($url) {
    $parts = explode("#", $url, 2);
    
    if (count($parts) == 1) {
      return array($parts[0], "");
    } else {
      return $parts;
    }
  }

  function filter($callback, &$sequence) {
    $result = array();
    
    foreach ($sequence as $item) {
      if (call_user_func_array($callback, array($item))) {
        $result[] = $item;
      }
    }
    
    return $result;
  }

  function update(&$dest, &$src) {
    foreach ($src as $k => $v) {
      $dest[$k] = $v;
    }
  }

  /**
   * Wrap PHP's standard error_log functionality.  Use this to
   * perform all logging. It will interpolate any additional
   * arguments into the format string before logging.
   *
   * @param string $format_string The sprintf format for the message
   */
  function log($format_string) {
    $args = func_get_args();
    $message = call_user_func_array('sprintf', $args);
    error_log($message);
  }

  function autoSubmitHTML($form, $title = "OpenId transaction in progress") {
    return ("<html>" . "<head><title>" . $title . "</title></head>" . "<body onload='document.forms[0].submit();'>" . $form . "<script>" . "var elements = document.forms[0].elements;" . "for (var i = 0; i < elements.length; i++) {" . "  elements[i].style.display = \"none\";" . "}" . "</script>" . "</body>" . "</html>");
  }
}
